DESCRIPTION (Applicant's Abstract): Emotional and behavioral disorders sufficiently serious to require mental health service intervention affect 11% to 20% of all adolescents in the US and cost $5 billion in mental health services each year. However, no evidence has been demonstrated that routine mental health care for adolescents actually produces desirable changes. To assess effectiveness of mental health care in adolescents, a comprehensive, standardized tool to measure outcomes is needed. This tool should provide valid, reproducible information about outcomes of care across diagnoses, clinical settings, interventions, and population groups; it must also be reasonably brief and inexpensive to administer. This tool could be used by providers, payers, and researchers to measure quality, appropriateness, and cost-effectiveness of care. The Adolescent Treatment Outcomes Module (ATOM), the sixth in a series of outcome assessment tools developed by the Centers for Mental Healthcare Research at the University of Arkansas for Medical Sciences, fulfills this need. ATOM consolidates relevant variables measured by a variety of existing instruments into a single, brief, comprehensive tool for routine outcomes measurement and monitoring in adolescents. The outcomes data resulting from the use of ATOM may be used by providers, payers, and researchers to develop and implement informed treatment decisions and improve the quality of mental health care for and outcomes in adolescents. The proposed research project will further develop and rigorously validate our adolescent emotional and behavioral problems module (ATOM) in several mental health service settings and geographic regions of the US by addressing four specific aims. These are to 1) establish ATOM as an appropriate instrument for assessing mental health outcomes in adolescents; 2) minimize the respondent and administrative test-taking burden of ATOM; 3) increase the psychometric specificity and sensitivity of ATOM; and 4) provide benchmarks for interpreting ATOM scales. The PI will collaborate with a cadre of well-established investigators in mental health outcomes measurement from a variety of mental health settings across the US.